Dual generator single power source for tandem pool and spa

ABSTRACT

A sanitizer generation system supplies power to a first and a second sanitizer generator. Each of the sanitizer generators is connected to a body of water by a circulation system. The system includes a power supply and a control system connected to the power supply and the sanitizer generators. The control system selectively delivers electric current from the power supply to the first and second sanitizer generators.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application is a divisional of application Ser. No.11/157,073, filed Jun. 20, 2005, entitled “Dual Generator Single PowerSource for Tandem Pool and Spa”, which is herein incorporated byreference in its entirety. The present application is also related toU.S. application Ser. No. 11/157,020, now U.S. Pat. No. 7,402,252,entitled “Automated Electrolyte Addition for Salt Water Pools, Spas, andWater Features” and U.S. application Ser. No. 11/157,041, now publishedApplication No. 2006/0283789, entitled “Pool and Spa Dual BodySanitization”, both of which are herein incorporated by reference intheir entireties.

BACKGROUND OF THE INVENTION

The present invention relates to systems and methods for sanitizingpools and spas. In particular, the present invention relates to a singlepower source system for generating a sanitizer for a tandem swimmingpool and spa.

Pools and spas have a circulation system that continually pumps waterfrom the pool or spa through a filter, heater, and sanitizer feed systembefore returning the water back to the pool or spa. The circulationsystem is necessary to maintain the body of water at sanitaryconditions. The water passes through the filter to reduce theaccumulation of foreign material, such as hair, soil, or solids, in thepool or spa. Once the water has been filtered, the water passes throughthe heater, where the water is heated prior to returning to the pool orspa.

In addition to filtering, pool and spa water also requires regularsanitization in order to maintain hygienic conditions. Allowingsanitation levels to either fall below or rise above requiredspecifications results in decreased efficiency of the system. Low levelsof chemical sanitizer in the pool or spa can contribute to algae blooms,bacterial breakouts, cloudiness in the water, and chemical imbalances. Amethod for sanitizing pool or spa water is by adding sodium chloride(NaCl) to the pool or spa and passing the water containing sodiumchloride through a chlorine generator where electrolysis converts thesodium chloride and water to sodium hypochlorite (NaOCl), by thefollowing reaction:

2NaCl(aq)+2H₂O|Cl₂(g)+H₂(g)+2NaOH(aq)|

NaOCl(aq)+H₂O+NaCl(aq)+H₂(g).

The chlorine generator is capable of being powered on and off dependingon the concentration of chlorine in the water. When there is asufficient level of chlorine in the pool or spa water, the chlorinegenerator is powered off and no reaction takes place. Thus, watercirculating through the circulation system is filtered and heated, butthe composition of the water is not altered. When the level of chlorinehas fallen to a desired setpoint, the chlorine generator is powered onand the sodium chloride and water passing through the chlorine generatoris converted to sodium hypochlorite. The chlorine generator remainspowered on until the concentration of chlorine in the water has reacheda desired steady state level.

Oftentimes, both a swimming pool and a spa are installed. Typically, thevolume of the pool is on average ten to fifteen times larger than thevolume of the spa. Despite this large difference in volumes, the cost ofthe equipment for treating the pool and spa is not significantlydifferent. The need for two power sources, one supplying power togenerate chlorine for the pool and the other supplying power to generatechlorine for the spa, can result in higher installation and maintenancecosts for the tandem pool and spa.

BRIEF SUMMARY OF THE INVENTION

A sanitizer generation system supplies power from a single source to afirst and a second sanitizer generator. Each of the sanitizer generatorsis connected to a body of water by a circulation system. The systemincludes a power supply and a control system connected to the powersupply and the sanitizer generators. The control system selectivelydelivers electric current from the power supply to the first and secondsanitizer generators.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a dual generator single power sourcesystem in accordance with the present invention.

DETAILED DESCRIPTION

FIG. 1 is a schematic diagram of sanitizer generation system 10 inaccordance with the present invention. Sanitizer generation system 10 isa dual sanitizing generator, single power source system that maintainsthe sanitizer concentration in two bodies of water, such as pool 12 aand spa 12 b, at a desired level by generating sanitizer for both bodiesof water with a single power source. Pool 12 a and spa 12 b may be anycombination of bodies of water to be treated. Using a single powersource to generate sanitizer for two bodies of water that are in closeproximity to one another is beneficial for reducing the cost ofmaintaining such systems by as much as 42%.

Sanitizer generation system 10 is connected to pool sanitizer generator14 a and to spa sanitizer generator 14 b by pool circulation system 16 aand spa circulation system 16 b, respectively, and generally includespower supply system 18 and control system 20. Power supply system 18supplies electric current to sanitizer generation system 10 from analternating current (AC) supply 22 and includes power supply box 24,transformer box 26, and rectifier box 28. Control system 20 includespool flow switch FSW_(a), spa flow switch FSW_(b), pool relay coil C_(a)and contacts C1 _(a) and C2 _(a), spa relay coil C_(b) and contacts C1_(b) and C2 _(b), and controller 30.

Sanitizer generation system 10 maintains the concentration of sanitizerin pool 12 a and spa 12 b at a desired level by powering sanitizergenerators 14 a and 14 b on and off as needed. When the level ofsanitizer concentration in pool 12 a falls to a desired setpoint, poolsanitizer generator 14 a is powered on to generate sanitizer for pool 12a. Likewise, spa sanitizer generator 14 b is powered on when the levelof sanitizer concentration in spa 12 b reaches a minimum level in orderto generate more sanitizer for spa 12 b.

Pool circulation system 16 a runs continuously and includes piping 32 a,circulation pump 34 a, filter 36 a, heater 38 a, sensor 39 a, sidestream 40 a, flow switch FSW_(a), and sanitizer generator 14 a.Circulation system 16 a connects pool 12 a to sanitizer generator 14 aand operates independently of pool and spa sanitizer generators 14 a and14 b. When there is a sufficient level of sanitizer in pool 12 a,sanitizer generator 14 a is powered off and water flows throughsanitizer generator 14 a without being reacted. When sanitizer isneeded, sanitizer generator 14 a is powered on while circulation system16 a transports water from pool 12 a through sanitizer generator 14 aand transports sanitized water back to pool 12 a. Circulation pump 34 ais typically positioned immediately downstream from pool 12 a and pumpswater from pool 12 a through piping 32 a and side stream 40 a.

Side stream 40 a of circulation system 16 a includes sanitization inletline 42 a and sanitization outlet line 44 a. Water enters sanitizergenerator 14 a through sanitization inlet line 42 a and leaves sanitizergenerator 14 a through sanitization outlet line 44 a. Sanitization inletline 42 a is plumbed to piping 32 a between filter 36 a and heater 38 aand connects pool 12 a to sanitizer generator 14 a. When sanitizationinlet line 42 a branches from piping 32 a, some of the water flowingthrough piping 32 a is diverted into sanitization inlet line 42 a at aflow rate lower than the flow rate of the water flowing through piping32 a.

Because a pump is not plumbed to side stream 40 a, a pressure drop isrequired across circulation system 16 a to maintain the flow of water inside stream 40 a at a velocity sufficient to pass the water throughsanitizer generator 14 a and back to pool 12 a. To create a pressuredrop across circulation system 16 a, sanitization inlet line 42 a isplumbed to piping 32 a immediately after filter 36 a. Positioningsanitization inlet line 42 a downstream from filter 36 a and upstreamfrom sanitizer generator 14 a also ensures that only a minimal amount offoreign material present in the water enters sanitizer generator 14 a.Without filter 36 a, foreign material could accumulate inside sanitizergenerator 14 a and reduce the life and performance of sanitizergenerator 14 a.

Alternatively, sanitization inlet line 42 a may also be plumbed topiping 32 a immediately after circulation pump 34 a. However, althoughpositioning sanitization inlet line 42 a between circulation pump 34 aand filter 36 a would provide an adequate pressure drop acrosscirculation system 16 a, the water entering sanitizer generator 14 awould be unfiltered. Thus, installation of an in-line strainer with asmall mesh in sanitization inlet line 42 a would be necessary to reducebuild-up of foreign material in sanitizer generator 14 a.

Pool flow switch FSW_(a) is plumbed to circulation system 16 a atsanitization inlet line 42 a and senses water flow from piping 32 athrough sanitization inlet line 42 a. Flow switch FSW_(a) serves as afailsafe for sanitizer generation system 10. Sanitizer generator 14 a isonly capable of being powered on if flow switch FSW_(a) senses waterflow through pool sanitization inlet line 42 a. If flow switch FSW_(a)does not sense water flow through sanitization inlet line 42 a, flowswitch FSW_(a) will not close and power is not supplied to sanitizergenerator 14 a.

The water leaves sanitizer generator 14 a at sanitization outlet line 44a, which connects to piping 32 a downstream from heater 38 a so that thewater from sanitization outlet line 44 a and the water from pool piping32 a combine prior to entering pool 12 a.

Spa circulation system 16 b includes piping 32 b, circulation pump 34 b,filter 36 b, heater 38 b, sensor 39 b, side stream 40 b, and flow switchFSW_(b) and functions in the same manner as pool circulation system 16a.

Sanitizer generators 14 a and 14 b are electrolytic cells that producesanitizer from the water and electrolyte pumped through side streams 40a and 40 b when sanitizer generators 14 a and 14 b are powered on,respectively. The water from pool 12 a and spa 12 b circulating throughcirculation systems 16 a and 16 b typically contain electrolyte that hasbeen added to pool 12 a and spa 12 b. When there is a sufficient levelof sanitizer in pool 12 a and spa 12 b, sanitizer generators 14 a and 14b are powered off and the water and electrolyte pass through withoutbeing reacted. In one embodiment, sanitizer generators 14 a and 14 b arewatertight tubes containing titanium plates coated with a preciousmetal. Although sanitizer generators 14 a and 14 b are shown in FIG. 1as being plumbed in parallel with heaters 38 a and 38 b, sanitizergenerators 14 a and 14 b may also be plumbed in-line with heaters 38 aand 38 b without departing from the intended scope of the presentinvention.

In an exemplary embodiment, pool and spa sensors 39 a and 39 b areconnected to pool and spa circulation systems 16 a and 16 b,respectively, and measure the oxidation-reduction potential (sanitizerconcentration) of the water passing through circulation systems 16 a and16 b. Sanitizer generation system 10 is at steady state and sanitizergenerators 14 a and 14 b are powered off when the sensed parameter (e.g.oxidation-reduction potential, pH, or conductivity) of the water incirculation systems 16 a and 16 b is at a desired level. When the sensedparameter of the water in pool 12 a reaches a desired setpoint, sensor39 a communicates to controller 30 that pool 12 a needs sanitization.Likewise, when the sensed parameter of the water in spa 12 b reaches adesired setpoint, sensor 39 b communicates to controller 30 that spa 12b needs sanitization.

Controller 30 is in communication with sensors 39 a and 39 b and isconnected to power supply source 18 and relay coils C_(a) and C_(b)through pool sanitization enable 46 a and spa sanitization enable 46 b.Pool sanitization enable 46 a enables plug 50 a. Spa sanitization enable46 b enables plug 50 b. In one embodiment, controller 30 is an Acu-TrolAK2100D controller with the capability to monitor oxidation-reductionpotential.

Pool sanitizer generator 14 a can only be activated if two conditionsare met: (1) sensor 39 a communicates to controller 30 that sanitizer isneeded in pool 12 a, and (2) flow switch FSW_(a) senses that there iswater flow through pool sanitization inlet line 42 a. If both conditionsare met, controller 30 supplies electric current to pool enable plug 50a. Current is supplied to pool enable plug 50 a through power enableoutlet 46 a. AC supply box 22 provides an alternating current to powersupply system 18. Power supply box 24 houses a primary transformer,current driver, and main relay switch. Transformer box 26 converts thealternating current to the voltage required to run sanitizer generators14 a and 14 b. Rectifier box 28 converts the alternating current to adirect current and houses a rectifier set, cooling block, and mechanicalrelay set.

Current is supplied to pool enable plug 50 a via outlet 46 a to energizepool relay coil C_(a). When energized, pool relay coil C_(a) closes poolrelay contacts C1 _(a) and C2 _(a), allowing electric current from powersupply system 18 to reach pool sanitizer generator 14 a. Once poolsanitizer generator 14 a is powered on, the water and electrolyteentering pool sanitizer generator 14 a through pool sanitization inletline 42 a is reacted and converted to a sanitizer solution.

In addition to controller 30 enabling pool sanitization enable plug 50a, flow switch FSW_(a) must also sense water flow through poolsanitization inlet line 42 a for pool sanitizer generator 14 a to poweron. When flow switch FSW_(a) senses water flow through pool sanitizationinlet line 42 a, flow switch FSW_(a) closes and electric current passesthrough relay coil C_(a). If flow switch FSW_(a) does not sense waterflow through pool sanitization inlet line 42 a, flow switch FSW_(a)remains open and sanitizer generator 14 a cannot be powered on eventhough pool enable plug 50 a is enabled. If electric current cannotreach transformer box 26 or relay coil C_(a), sanitizer generator 14 acannot be activated.

Pool sensor 39 a continuously communicates the amount of sanitizer inthe water in pool circulation system 16 a to controller 30. As sanitizeris added to the water in pool circulation system 16 a, the sanitizerlevel of the water increases. Once the sanitizer level of the waterreaches a desired maximum level, there is a sufficient amount ofsanitizer in pool 12 a and controller 30 cuts off electric current topool sanitization enable plug 50 a. When pool sanitization enable plug50 a is not enabled, pool relay coil C_(a) is de-energized, causing poolrelay contacts C1 _(a) and C2 _(a) to open and cut off power to poolsanitizer generator 14 a.

Spa circulation system 16 b, spa flow switch FSW_(b), spa sensor 39 b,spa relay coil C_(b), spa relay contacts C1 _(b) and C2 _(b), and spasanitizer generator 14 b function and interact with controller 30 in thesame manner as pool circulation system 16 a, pool flow switch FSW_(a),pool sensor 39 a, pool relay coil C_(a), pool relay contacts C1 _(a) andC2 _(a), and pool sanitizer generator 14 a.

Sanitizer generation system 10 has the capability to supply power tosanitizer generators 14 a and 14 b simultaneously, or one at a time,depending on the needs of pool 12 a and spa 12 b. When only one ofsanitizer generators 14 a and 14 b is activated, full power is sent tothe activated generator from power supply system 18. When sanitizergenerators 14 a and 14 b are activated simultaneously, the power sent toeach generator 14 a and 14 b is split. Thus, the output of eachgenerator 14 a and 14 b is also reduced. Although FIG. 1 depictssanitizer generators 14 a and 14 b as being equal in size, sanitizergenerators 14 a and 14 b may also be sized depending on the desiredoutput. Because pool 12 a is typically much larger than spa 12 b, pool12 a generally requires more sanitizer than spa 12 b. Thus, it may bemore effective for pool sanitizer generator 14 a to be larger than spasanitizer generator 14 b. In addition, although FIG. 1 discusses asingle power source sanitizer generation system supplying power to twobodies of water, the sanitizer generation system can supply power tomore than two bodies of water without departing from the intended scopeof the present invention.

Although the present invention is discussed using an automated system toactivate and deactivate pool and spa sanitizer generators 14 a and 14 b,sanitizer generation system 10 can also be run manually, without acontroller. Power is supplied to sanitizer generation system 10 at alevel such that both pool and spa sanitizer generators 14 a and 14 b runcontinuously. While power is continuously supplied to sanitizergeneration system 10, it is supplied at a trickle in order to avoidover-chlorination of either pool 12 a or spa 12 b.

The sanitizer generation system of the present invention provides asingle power source for activating more than one sanitizer generator inorder to reduce the cost of maintaining the sanitizer concentration ofmultiple bodies of water at a desired level. The sanitizer generationsystem is capable of supplying power to either only one sanitizergenerator at a time, or to more than one sanitizer generator at a time.When a sensor in a circulation system circulating water from a body ofwater communicates to a controller that the sanitizer concentration inthe body of water needs to be increased, the controller enables a poolsanitization enable plug to supply electric current through a powersupply to the sanitizer generator connected to the body of water. Theelectric current provides the power necessary to run the sanitizergenerator.

In addition to a need for sanitizer, a flow switch in the circulationsystem must also sense water flow through the circulation system inorder for the sanitizer generator to be powered on. If the flow switchsenses water flow in the circulation system, electric current passesthrough the power supply and energizes a relay coil. When the relay coilis energized, it closes a pair of relay contacts and allows electriccurrent flowing from the power supply to reach the sanitizer generator.Once the sanitizer concentration in the body of water has reached adesired maximum level, the controller cuts off electric current to theenable plug, which de-energizes the relay coil, causing the relaycontacts to open. When the relay contacts are open, no power is suppliedto the sanitizer generator. If at any time the flow switch does notsense water flow through the circulation system, the flow switch isopened and electric current cannot reach the sanitizer generator.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

1. An automated method of sanitizing a first body of water and a secondbody of water with electric current from a single shared power source,the method comprising: (a) circulating water from the first body ofwater through a first circulation system, the first circulation systemhaving a first sanitizer generator; (b) circulating water from thesecond body of water through a second circulation system, the secondcirculation system having a second sanitizer generator; (c) sensing aparameter of the water in the first body of water related to a need forsanitization; (d) selectively delivering electric current from the powersource to the first sanitizer generator to generate sanitizer for thefirst body of water when sanitization is needed; (e) sensing a parameterof the water in the second body of water related to a need forsanitization; and (f) controlling with a shared control system,selective delivery of electric current from the shared power source tothe second sanitizer generator to generate sanitizer for the second bodyof water when sanitization is needed.
 2. The method of claim 1, andfurther comprising: (g) sensing the water flow through the firstsanitizer generator; and (h) sensing the water flow through the secondsanitizer generator.
 3. The method of claim 1, wherein selectivelydelivering electric current from the shared power source to the firstsanitizer generator is based on the need for sanitization of the firstbody of water and whether there is water flow through the firstsanitizer generator.
 4. The method of claim 1, wherein selectivelydelivering electric current from the shared power source to the secondsanitizer generator is based on the need for sanitization of the secondbody of water and whether there is water flow through the secondsanitizer generator.
 5. A method of sanitizing a first body of water anda second body of water with electric current from a single power source,the method comprising: (a) circulating water from the first body ofwater through a first circulation system, the first circulation systemhaving a first sanitizer generator; (b) circulating water from thesecond body of water through a second circulation system, the secondcirculation system having a second sanitizer generator; and (c)controlling, with a shared control system, delivery of electric currentfrom the power source to the first sanitizer generator and the secondsanitizer generator.
 6. The method of claim 5, wherein the first andsecond sanitizer generators are different sizes.
 7. The method of claim5, wherein electric current is delivered from the shared power sourcebased upon a sensed need for sanitizer in the first and second bodies ofwater.
 8. The method of claim 5, wherein electric current iscontinuously delivered from the shared power source to both the firstand the second sanitizer generators.